The common cockle (''Cerastoderma edule'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of edible saltwater

clam Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that are edible and live as infauna, spending most of their lives halfway buried in the sand of the seafloor or riverbeds. Clams have two she ...

, a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

in the family

Cardiidae A cockle is an edible marine bivalve mollusc. Although many small edible bivalves are loosely called cockles, true cockles are species in the family Cardiidae. MolluscaBase eds. (2022). MolluscaBase. Cardiidae Lamarck, 1809. Accessed through: W ...

, the cockles. It is found in waters off Europe, from Iceland in the north, south into waters off western Africa as far south as Senegal. The ribbed oval shells can reach across and are white, yellowish or brown in colour. The common cockle is harvested commercially and eaten in much of its range.

Taxonomy and naming

The common cockle was one of the many invertebrate species originally described by

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

in the landmark 1758 10th edition of ''

Systema Naturae ' (originally in Latin written ' with the ligature æ) is one of the major works of the Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial nomen ...

'', where it was given its old binomial name ''Cardium edule''. The species name is derived from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

adjective ''ĕdūlis'' "edible". Italian naturalist

Giuseppe Saverio Poli Giuseppe Saverio Poli (26 October 17467 April 1825) was an Italian physicist, biologist and natural historian. His collections, together with those stored in the Royal Bourbon Museum, were the foundation of the Zoological Museum of Naples. Th ...

erected the genus ''

Cerastoderma ''Cerastoderma'' is a genus of marine bivalves in the family Cardiidae. It includes the common cockle ''Cerastoderma edule.'' Fossil records This genus is known in the fossil records from the Paleocene to the Quaternary (age range: from 58.7 t ...

'' in 1795, making the common cockle the type species as ''Cerastoderma edule''. The genus name is derived from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

words ''keras'' "horn" and ''derma'' "skin". For many years it was referred to by both names. Other common names in English are edible cockle and common edible cockle. On account of its heart-like shape, it is called the "heart mussel" in German and Scandinavian languages (''Hertzmuschel'' and ''Hjertemusling'', respectively).Davidson, Alan.
The Oxford Companion to Food
', p. 201 (

Oxford University Press Oxford University Press (OUP) is the university press of the University of Oxford. It is the largest university press in the world, and its printing history dates back to the 1480s. Having been officially granted the legal right to print books ...

, 2014).

Description

It typically reaches from to in length,Considine, Douglas and Considine, Glenn.
Van Nostrand's Scientific Encyclopedia
', p. 2086 (Springer Science & Business Media, 2013). but sometimes it reaches . The shells are pale or whitish yellow, grubby white, or brown. The shell is oval, and covered by ribs, which are flattened in the middle part of the shell. The digestive glands are light brown to dark green. In contrast, the similar lagoon cockle has an elongated shell posteriorly, black digestive glands and is found in substrate of stagnant water.

Distribution and habitat

This species is found in

coast The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in n ...

al areas of the northern and eastern

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

. It is widely distributed from Iceland and Norway in Europe, to Senegal along the coast of west Africa. The common cockle is one of the most abundant species of molluscs in

tidal flats Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal fl ...

located in the bays and estuaries of Europe. It plays a major role as a source of food for

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

, and wading

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

''Cerastoderma edule edule''
Right and left valve of the same specimen: File:Cerastoderma edule 01.jpg, Right valve File:Cerastoderma edule 02.jpg, Left valve ''Cerastoderma edule belgicum''
Right and left valve of the same specimen: File:Cerastoderma edule belgicum 01.jpg, Right valve File:Cerastoderma edule belgicum 02.jpg, Left valve ''Cerastoderma edule maculatum''
Right and left valve: File:Cerastoderma edule maculatum 01.jpg, Right valve File:Cerastoderma edule maculatum 02.jpg, Left valve

Ecology

This species is a

filter feeder Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...

, meaning that it feeds by straining water to obtain suspended matter and food particles.Dauvin, Jean-Claude.
Biological heritage and food chains
', p. 25 (Quae,

Centre de coopération internationale en recherche agronomique pour le développement The French Agricultural Research Centre for International Development (CIRAD) is a French agricultural research and international cooperation organization working for the sustainable development of tropical and Mediterranean regions. It is a publi ...

, 2006). Water is inhaled through an inhalant siphon, and exhaled through an exhalant siphon. It tolerates a wide range of salinity (

euryhaline Euryhaline organisms are able to adapt to a wide range of salinities. An example of a euryhaline fish is the molly (''Poecilia sphenops'') which can live in fresh water, brackish water, or salt water. The green crab (''Carcinus maenas'') is an e ...

), and wide range of temperatures (

eurythermic A eurytherm is an organism, often an endotherm, that can function at a wide range of ambient temperatures. To be considered a eurytherm, all stages of an organism's life cycle must be considered, including juvenile and larval stages. These wide ...

), which helps to explain its very extensive

range Range may refer to: Geography * Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra) ** Mountain range, a group of mountains bordered by lowlands * Range, a term used to i ...

. It has a first spawning period in early summer, and a second one in the fall. Lifespan is typically five to six years, though it may perish earlier due to predation by humans as well as

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

flounder Flounders are a group of flatfish species. They are demersal fish, found at the bottom of oceans around the world; some species will also enter estuaries. Taxonomy The name "flounder" is used for several only distantly related species, thou ...

, and various birds especially including

oystercatcher The oystercatchers are a group of waders forming the family Haematopodidae, which has a single genus, ''Haematopus''. They are found on coasts worldwide apart from the polar regions and some tropical regions of Africa and South East Asia. The e ...

s. A green shore crab (''

Carcinus maenas ''Carcinus maenas'' is a common littoral crab. It is known by different names around the world. In the British Isles, it is generally referred to as the shore crab, or green shore crab. In North America and South Africa, it bears the name eur ...

'') can consume up to 40 common cockles a day, eating smaller cockles (under 1.5 cm diameter) much more quickly than larger ones. Hence they could have a greater impact in lean seasons where cockles did not grow so quickly.

Parasites and diseases

The

cercozoa Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major eu ...

n species '' Marteilia cochillia'' is a parasite of the common cockle, having caused a collapse in commercial harvests of cockle beds in Galicia in 2012. A survey of cockle beds in Galicia found that infestation by the gregarine parasite '' Nematopsis'' was widespread, and that the most common pathological finding was disseminated neoplasia.

Uses

These animals were probably a significant food source in hunter-gatherer societies of

prehistoric Europe Prehistoric Europe is Europe with human presence but before the start of recorded history, beginning in the Lower Paleolithic. As history progresses, considerable regional irregularities of cultural development emerge and increase. The region o ...

, and the clay remains of shell-imprints have been found. The clay is imprinted with fine decorations, repetitions of the distinct curved ridges, undulating lines and/or edges characteristic to the cockle shell, a natural resource of coastal waters.

Cardial ware Cardium pottery or Cardial ware is a Neolithic decorative style that gets its name from the imprinting of the clay with the heart-shaped shell of the '' Corculum cardissa '', a member of the cockle family Cardiidae. These forms of pottery a ...

is the name of the

Neolithic The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts ...

pottery from maritime cultures that colonized Mediterranean

shores Shores is a band from Grand Rapids, Michigan, and Minneapolis, Minnesota. The band is often described as "slowcore". Shores began as a recording project between guitarist, vocalist and bass guitarist Brian Przybylski, and drummer John Massel in s ...

c. 6000 – 5,500 BC, this name being based upon the old binomial name of the species: ''Cardium edule''. In the 1800s, a song called "

Molly Malone "Molly Malone" (also known as "Cockles and Mussels" or "In Dublin's Fair City") is a traditional song set in Dublin, Ireland, which has become its unofficial anthem. A statue representing Molly Malone was unveiled on Grafton Street by then Lo ...

" was first published (also known as "Cockles and Mussels"), later becoming the unofficial song of

Dublin Dublin (; , or ) is the capital and largest city of Republic of Ireland, Ireland. On a bay at the mouth of the River Liffey, it is in the Provinces of Ireland, province of Leinster, bordered on the south by the Dublin Mountains, a part of th ...

, Ireland. The lyrics describe Molly Malone selling the common cockle in the streets of that city.

As food

Ecomare - kokkelbank (wad-cocksdorp-kokkelbank-90-idp)

This cockle is cooked and eaten in several countries (including the United Kingdom, France, Germany, Ireland, Japan, Portugal and Spain). It is also sometimes eaten pickled, or raw. An important species for the fishing industry, it is commercially fished in the United Kingdom, Ireland and France by suction dredge and also raking by hand. Previously the greatest catch was from the Netherlands, but now fisheries restrictions have been put in place due to environmental concerns. Similar measures have been established elsewhere, for example in Scotland where dredging with vehicles is prohibited, and in parts of England and Wales where only old-fashioned hand-gathering is permitted (using a long plank that is rocked back and forth on the sand). This species is also used in

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...

. Farming of cockles is ongoing in the UK, the Netherlands and Portugal. However, production in those countries has not been very stable; for example, production fell from 107,800 tons in 1987 to 40,900 tons in 1997.Spencer, Brian.
Molluscan Shellfish Farming
', p. 103 (John Wiley & Sons, 2008). In addition to being a food source, their shells have also been used industrially as a source of

lime Lime commonly refers to: * Lime (fruit), a green citrus fruit * Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide * Lime (color), a color between yellow and green Lime may also refer to: Botany ...

. Gathering this species can be dangerous. In 2004, the incoming tide at

Morecambe Bay Morecambe Bay is a large estuary in northwest England, just to the south of the Lake District National Park. It is the largest expanse of intertidal mudflats and sand in the United Kingdom, covering a total area of . In 1974, the second larges ...

in England caused 23 cockle-gatherers to die.Chambers, Paul.
British Seashells: A Guide for Collectors and Beachcombers
', p. 158 (

Casemate Publishers Casemate Publishers is a publishing company based in the Philadelphia suburbs that specializes in producing printed military history books. They have published over 500 titles on military history. Many of their books are memoirs and historical o ...

, 2009).

References

External links

* {{Taxonbar , from=Q21124 Cardiidae Commercial molluscs Molluscs described in 1758 Taxa named by Carl Linnaeus Molluscs of the Atlantic Ocean Molluscs of the Mediterranean Sea Molluscs of the Black Sea Marine molluscs of Europe Bivalves of Europe Marine molluscs of Africa